As a conventional pneumatic radial tire, there is known one in which a plurality of land portion rows are formed by a plurality of main grooves that extend in the circumferential direction of the tread portion of a tire, a thin groove that extends in the tire circumferential direction is formed in the shoulder land portion row that is positioned on the tread end side among the plurality of land portion rows, and lug grooves are formed that extend in the tire width direction from the thin groove to the tread end (for example, refer to Patent Document 1).
In this type of pneumatic radial tire, it is possible to suppress eccentric wear of the tire with the thin groove, and also it is possible to drain water that has flowed into the thin groove to the outside in the tire width direction through the lug grooves.
[Patent Document 1] Japanese Unexamined Patent Application, First Publication No. H11-301214